Mixing devices are often applied in hydraulic heating installations and/or cooling installations, in order to be able to set a feed temperature independently of the exit temperature of a heat source or cold source. In floor heating installations for example, it is necessary to reduce the feed temperature which prevails at the exit side of a heating boiler. This in mixing devices is effected in a manner such that two differently temperature-controlled fluid flows are mixed with one another, in order to set a desired exit temperature. Thus, cooled fluid from the return can be admixed to the feed in a heating installation for example. Vice versa, the feed temperature can be increased in a cooling installation, by way of heated fluid from the return being admixed to the feed.
In automatically controlled heating installations or cooling installations, the mixing device as a rule is designed as a mixing valve which is moved by a servomotor. A mixing control device which can either be provided as a separate module or can be integrated into the control of a heating boiler is necessary for activating the servomotor. The individual installation components not only therefore need to be hydraulically but also electrically connected to one another, which entails a larger assembly effort for the heating fitter.